1. Field of the Invention
The invention relates to the field of air traffic and, more particularly, its object is a collision-avoidance method for aircraft and an optical set to be taken on board aircraft in order to implement it.
The need for aircraft to be able to maneuver in conditions of low visibility or in dense traffic zones necessitates the use of systems enabling the avoidance of collisions.
2. Description of the Prior Art
Anti collision systems using transmission by radio or by radar waves have been developed.
Systems known as TCAS (Traffic Alert and Collision Avoidance Systems) use interrogators on the ground and transponders carried by aircraft capable of responding as interrogated, if necessary by the addition, to their response code, of information elements relating for example to their altitude. These systems, of the secondary surveillance radar type, are complicated systems that are very costly.
Other types of systems have been developed, using methods of communication by radio waves and therefore requiring radio dialog for the localization of danger or threats. These systems, apart from their complexity, cannot be used to obtain the fast responses that are indispensable in the event of a risk of collision, and some Of them are subject to the hazards of transmission in certain particular conditions, for example fading, echos, etc.